Create an outbound email case for a customer by email.

create_case.rb

require 'desk_api' # @see https://github.com/forcedotcom/salesforce-deskcom-api
# authenticate `DeskApi` with your Desk.com instance

#####
# FIND OR CREATE CUSTOMER
#####
# you should get the customer data from your system
customer_data = {
  first_name: 'John',
  last_name: 'Smith',
  emails: [{ type: 'home', value: 'jsmith@example.com' }]
}

# find the customer by email address
query  = customer_data.emails.map { |x| x[:value] }.join(',')
search = DeskApi.customers.search(email: query)

if search.total_entries == 0 # create customer if he doesn't exist
  customer = DeskApi.customers.create(customer_data)
else # use the existing customer
  customer = search.entries.first
end

#####
# CREATE THE OUTBOUND CASE
#####
# this is the email you want to send to your customer
email_data = {
  direction: 'out',
  status: 'pending',
  subject: 'Email Subject',
  body: 'Email Message',
  from: 'Laura Agent <lagent@example.com>',
  to: 'John Smith <jsmith@example.com>',
  cc: 'Mark Snider <msnider@example.com>',
  bcc: 'Reid Wheeler <rwheeler@example.com>'
}

# additional ticket information
ticket_data = {
  type: 'email',
  subject: email_data[:subject],
  priority: 4,
  status: 'pending',
  labels: ['Follow Up'],
  message: email_data,
  custom_fields: { level: 'vip' },
  _links: {
    customer: customer.get_self,
    assigned_user: { href: '/api/v2/users/1', class: 'user' },
    assigned_group: { href: '/api/v2/groups/1', class: 'group' }
  }
}

# create the case
ticket = DeskApi.cases.create(ticket_data)
# at this point the case has been created
# and the email is queued to be sent